Method of manufacturing a non-woven fibrous sheet



y 1953 J. H. GOLDMAN ,2

METHOD OF MANUFACTURING A NON-WOVEN FIBROUS SHEET Filed Feb. 5. 1953 IN V EN TOR.

goshuo H.Go|dm0n ATTORNEY METHOD OF MANUFACTURING A NON-WOVEN FIBROUS SHEET Joshua H. Goldman, Hadlyme, Conn. Application February 5, 1953, Serial'No. 335,37 6

Claims. (G1. 154-33 My present invention relates .to a fibrous web and the method of making the same.-

The principal object of the present "invention is to provide a web of fibrous material in-which the fibers are disposed ina heterogeneous non-parallel mass of uniform weight. 7

Another object of the present invention is to provide a .thin heterogeneous fibrous web having tensile strength longitudinally and transversely in the plane of the web as well as at right angles to the planeof the web.

A further. object of the present invention is to provide a novel method of manufacturing a fibrous web comprising a heterogeneous mass ojf 'nornpara llel fibers. Another objectof the present invention is to provide a method of manufacture which is suitable for either method of manufacture, and

Fig. 2 is a diagrammatic view of an alternative form of apparatus and method of manufacture.

Thepresent invention constitutes an improvement over my United States Patent No. 2,039,312 entitled Reinforced Carded Webs.

It has been found desirable to provide a cotton or other fibrous material in an extremely thin non-woven Web composed of intertwined fibers. Such a web has many uses both in industry .and in medicine. For example, it can be made of absorbent material and .When manufactured by the present method will have high absorbent qualities. In the patent hereinabove referred to, the web produced by the method shown therein will have considerable tensile strength longitudinally in the plane of the web, but will be found to separate quite easily transversely to the plane of the web. The present invention provides a novel method of manufacturing a fibrous web which will result in considerable tensile strength both longitudinally and transversely in the plane of the web.

The desired web can be made of any fibrous material, either natural or artificial, or blends thereof. The method of the present invention is designed to intermingle the .fibers in a heterogeneous mass of non-parallel fibers, giving the resultant web tensile strengthin every direction in the plane of the web.

Referring to the drawings, Fig. 1 shows the disposition of the various portions of standard textile machinery components for carrying outthe process of the present invention. Thefibers .are first run through the conventional machines resulting in the picker lap 10. The picker lap 10 then passes through the conventional feed rolls 11 and United States Patent over the lickerin 12.1'otating in a clockwise direction. The lickerin 12 is preferably provided with metallic clothing -1324 pitch, 12 teeth to the inch. The lickerin should be rotated at a surface speed of approximately 1200 feet per minute. Adjacent the lickerin, I provide the cylinder 14, also rotating clockwise and having surface teeth pitched in the same direction as the metallic clothing 13' on the lickerin -12. The cylinder 14 is, therefore, provided with metallic clothing 15-28 pitch and 16 teeth to the inch. Thecylinder 14 should have a surface speed much greater than the lickerin 12 and approximately 2500 feet per minute. The picker lap 1.0 is, therefore, pulled by the cylinder 14 from the lickerin 12 at a high rate ofspeed, causing an attenuation of the-lap, resulting in a thin web of uniform weight.

Adjacent the cylinder 14 i now provide a fancy or stripper 16 rotating in a counterclockwise direction at a surface speed greater than the surface speed of the cylinder 14. A surface speed of 3000 feet per minute is preferable. It should be noted at this point that the surface speeds given herein are for comparative purposesonly andmay be varied provided the speed differentials indicated herein are substantially maintained. The stripper 16 is provided with a #33 to #35 flexible clothing, or may be provided with metallic clothing, 32 pitch and 20 teeth to the inch.

The highspeed counterclockwise rotation of thestripper 16 will clear the attenuated lap from the cylinder 14 and deposit the fibers uniformly upon the condenser 37 rotating in a counterclockwise direction. The condenser 17 may be covered with rubber or wool. At this point, the fibers impinging on the surface of the condenser 17 from the fancy or stripper 1d are in a uniformly distributed non-parallel heterogeneous state. The condenser 1'7 rotates at a surface speed variable from 10 to 60 feet per minute, causing a crowding of the heterogeneous mass of fibers upon its surface as it comes from the stripper 16.

The lickerin 12, cylinder 142-, stripper 16 and condenser .17 are preferably positioned as shown in Fig. 1, so that the fibers leave the cylinder 14 tangentially at right angles toa center line drawn through thecenters of the cylinder 14 and stripper 16. The condenser 17 must be so disposed that the spray of fibers 18 impinge directly uponit.

The various parts hereinabove described are provided with appropriate shields 19 and 20. Theshield 19' extends around the upper surface of the lickerin 12, across and around the cylinder 14 and around the lower portion of the stripper .16, as shown in Pig. 1. The shield 20 extends around the lower portion of the lickerin 12, then around part of the surface of the cylinder 14 and around the upper surface of the condenser 1'7, also as shown in Fig. 1. These shields are preferably positioned approximately .020" zfromthe surfaces of the various rolls. This small clearance will prevent fly due to. the centrifugal force, it will protect the personnel, and it willconfine air currents caused by the toothed surfaces at highspeed. The small clearance between the shieldsand therolls provides for a boundary layer of .air which acts to aid the untangling of the fibers. Note that the position of the shield 19 around the stripper 16 and the shield 20 extendingpart way between the cylinder 14. and condenser 17 insures the proper direction of the spray of fibersupon the condenser.

Directly below the condenser .17 and in contact therewith is a wetting roll 21 immersed in a pan 22. The pan 22 may contain Water or some dilute adhesive such as starch orlatex which may :be varied to conform to any coating or finishing.operationwhichrnay be desirable to perform on the final product. For example, the pan may contain solvent for one of atmixture of fibers acting as a binder in the dissolved state, or it may contain a chemical that will gelatinize or hydrolize the surface of the fibers, thus causing them to be adhesive and allowing them to be bonded when subjected to subsequent pressure in the squeeze rolls. The wetting roll rotates clockwise and the heterogeneous mass of fibers passing between the condenser 17 and wetting roll 21 will become impregnated with the wetting agent. From this point, the resultant web passes between the conventional squeeze rolls 23 around the drying cans 24 and into the batcher 25 which winds the same into a roll or web 26. 7

It will be found that by the above process a fibrous lap weighing 16 ounces to the square yard will result in a heterogeneous web of non-parallel fibers of approximately 100 grains to the square yard, or approximately 70 yards to the pound when the condenser speed is 60 feet per minute. The thickness and weight of the finished web may be varied by varying the speed of the condenser 17 so that heavier webs can be formed. Because of the non parallel intermeshing of the fibers, the resultant web will have considerable tensile strength in any direction in the plane of the web. The process hereinabove described lends itself to any type of natural or artificial fiber or any blends thereof.

As an alternative method of removing the web from the condenser 17, the method shown in Fig. 2 may be used. In this form, the condenser 27 may be provided with 26 pitch, 16 teeth to the inch dotfer wire instead of the rubber or wool covering and a conventional doffer comb 28 may be used to remove the web from the condenser and pass it between a pair of wetting rolls 29, the lower of which is immersed in a pan 30. From this point, the web can be passed through the squeeze rolls 31 and drying cans and batcher as shown in Fig. 1. An appropriate shield 32 may be provided to properly direct the movement of the web from the condenser 27 to the wetting rolls 29.

The above described machinery and process can readily be used to form webs of any fibrous material such as asbestos, paper or wood pulp, or glass fibers. instances a bonding agent may be used in the wetting process or a subsequent bonding agent applied to the finished web in any desirable manner. The main feature of the present invention is, therefore, themethod of handling a fibrous structure resulting in a disruption of the parallelism of the fibers to form a non-woven heterogeneous mass of non-parallel fibers evenly distributed and of substantially uniform weight throughout. When properly processed, the resultant web can be made extremely thin, extremely light, and with a high tensile strength in every direction in the plane of the web. The product can be made highly absorbent, as, for example, with cotton fibers. It can also be treated to make it waterproof. It can be dyed and it can be stilfened. The web can be used for insulation, for wiping cloths, and in many other applications. Other advantages will be readily apparent to a person skilled in the art.

I claim:

1. The method of forming a non-woven web of fibrous material having a heterogeneous mass of non-parallel and non-oriented fibers from a picker lap or other source of fiber stock, comprising the steps of attenuating the lap or fiber stock by passing said lap or fiber stock over a pair of rollers shielded to cause air currents and the fibers to follow the periphery of said rollers, the first roller rotating clockwise at a minimum surface speed of 1200 feet per minute and the second roller adjacent said first roller rotating clockwise at a minimum surface speed of 2500 feet per minute, and throwing the discrete fibers by centrifugal force in a heterogeneous, non-oriented stream of uniform density upon a collecting surface to form a nonwoven web, said fibers being thrown by a third shielded roller adjacent said second roller and rotating counterclockwise at a minimum surface speed of 3000 feet per minute.

2. The method of forming a non-woven web of fibrous material having a hetergeneous mass of non-parallel and In some non-oriented fibers from a picker lap or other source of fiber stock, comprising the steps of attenuating the lap or fiber stock by passing said lap or fiber stock over a pair of rollers shielded to cause air currents and the fibers to follow the periphery of said rollers, the first roller rotating clockwise at a minimum surface speed of 1200 feet per minute and the second roller adjacent said first roller rotating clockwise at a minimum surface speed of 2500 feet per minute, throwing the discrete fibers by centrifugal force in a heterogeneous, non-oriented stream of uniform density upon a collecting surface to form a non-woven web, said fibers being thrown by a third shielded roller adjacent said second roller and rotating counterclockwise at a minimumsurface speed of 3000 feet per minute, wetting the fibers with a bonding agent, squeezing the fibers into a thin heterogeneous, non-oriented web, and drying the web.

3. The method of forming a non-woven web of fibrous material having a heterogeneous mass of non-parallel and non-oriented fibers from a picker lap or other source of fiber stock, comprising the steps of attenuating the lap or fiber stock by passing said lap or fiber stock over a pair of rollers shielded to cause air currents and the fibers to follow the periphery of said rollers, the first roller rotating clockwise at a minimum surface speed of 1200 feet per minute and the second roller adjacent said first roller rotating clockwise at a minimum surface speed of 2500 feet per minute, breaking up the attenuated fibers into discrete non-parallel, non-oriented fibers, and throwing the discrete fibers by centrifugal force in a heterogeneous, non-oriented stream of uniform density upon a collecting surface to form a non-woven web, said fibers being thrown by a third shielded roller adjacent said second roller and rotating counterclockwise at a minimum surface speed of 3000 feet per minute.

4. The method of forming a non-woven web of fibrous material having a heterogeneous mass of non-parallel and non-oriented fibers from a picker lap or other source of .fiber stock, comprising the steps of attenuating the lap or fiber stock by passing said lap or fiber stock over a pair of rollers shielded to cause air currents and the fibers to follow the periphery of said rollers, the first roller rotating clockwise at a minimum surface speed of 1200 feet per minute and the second roller adjacent said first roller rotating clockwise at a minimum surface speed of 2500 feet per minute, breaking up the attenuated fibers into discrete non-parallel, non-oriented fibers, throwing the discrete fibers by centrifugal force in a heterogeneous, non-oriented stream of uniform density upon a collecting surface to form a non-woven web, said fibers being thrown by a third shielded roller adjacent said second roller and rotating counterclockwise at a minimum surface speed of 3000 feet per minute, wetting the fibers with a bonding agent, squeezing the fibers into a thin heterogeneous, nonoriented web, and drying the web.

5. The method of forming a non-woven fibrous web having uniform tensile strength in all directions in the plane of the web from a picker lap or other source of fiber stock, comprising the steps of attenuating the lap or fiber stock, destroying the relation of the fibers to form a non-parallel, non-oriented stream, and throwing the nonoriented fibers on a slowly rotating cylinder, said attenuating, destroying the parallel relation and throwing of the fibers being performed by passing said lap or fiber stock over a series of three rollers shielded to cause air currents and the fibers to follow the periphery of the rollers and operating at progressively higher surface speeds, the minimum surface speed of the first roller being 1200 feet per minute, the first two rollers rotating clockwise and the last roller rotating counterclockwise.

(Other references on following page) 5 UNITED STATES PATENTS Brooks Nov. 21, 1933 Hurst Sept. 22, 1936 Hurst et a1 Sept. 22, 1936 Miller Oct. 24, 1944 Locke July 2, 1946 Ramsdell Oct. 22, 1946 Bacon June 1, 1948 Buresh Oct. 19, 1948 Wilson et a1 Aug. 2, 1949 Ramsdell July 4, 1950 6 Ramsdell Dec. 5, 1950 Browne Oct. 16, 1951 Lannan Mar. 11, 1952 Sheidley Nov. 25, 1952 Phillips et a1 Aug. 18, 1953 Slayter Sept. 29, 1953 Labino Oct. 19, 1954 Kaufman et al Apr. 16, 1957 FOREIGN PATENTS Great Britain Nov. 20, 1934 

